Eigen

The eigenvalue (modal) visualization provides insights into the dynamic characteristics of the structure. It includes the following features:

  • Mode Shapes: Visual representation of how the structure deforms under specific vibration modes.

  • Natural Frequencies or Periods: Display of corresponding frequencies or periods for each mode, enabling detailed analysis of structural dynamics.

  • Animation: Dynamic visualization of the mode shapes to better understand the structural response.

Using the visualization tools, you can:

  1. Analyze the vibration patterns of the structure.

  2. Identify critical modes that may impact structural performance.

  3. Evaluate the effectiveness of design modifications in improving dynamic behavior.

import opstool as opst
import opstool.vis.plotly as opsvis

Here, we use a built-in example from opstool, which is an example of a deck arch bridge model primarily composed of frame elements and shell elements.

opst.load_ops_examples("ArchBridge")
# or your model code here

We use the opstool.vis.plotly.set_plot_props() function to predefine some common visualization properties, which will affect all subsequent visualizations of models, eigenvalues, and responses.

opsvis.set_plot_props(point_size=0, line_width=3)

Save the eigen analysis results

Although not mandatory, you can use the save_eigen_data function to save eigenvalue analysis data, which can help you better understand how opstool operates.

Parameters:

  • odb_tag: Specifies the label for the output database.

  • mode_tag: Specifies the number of modes to save. Modal data within the range [1, mode_tag] will be saved.

For detailed usage, please refer to the opstool.post.save_eigen_data().

opst.post.save_eigen_data(odb_tag=1, mode_tag=6)
OPSTOOL™ ::  Eigen data has been saved to G:\opstool\docs\.opstool.output/EigenData-1.zarr!